Contemporary hard disk drives are faced with severe challenges. They must operate wherever their users decide to operate them, in environments where the hard disk drive must operate outside of room temperature.
When a hard disk drive is too hot, many operating problems develop. Heat tends to decay the material of the rotating disk surfaces on which the data is stored. The mechanical component tolerances degrade due to differences in their coefficients of thermal expansion. The pressure at the air bearing surface will change due to the high temperature. The breakdown of lubricants used in the hard disk drive is accelerated. The sensitivities due to thermal asperities during read operations is increased. The effects of thermal pole tip protrusion are maximized.
When the hard disk drive is too cold, other operating problems develop. The thermal coercivity of the disk media is lowered, degrading the ability to write data to tracks on the disk surfaces. The pressure at the air bearing surface will change due to the low temperature. It takes longer to start up the hard disk drive when it is cold, due to the viscosity of the lubricant in the spindle motor. The effects of thermal pole tip protrusion are minimized.
Today, many hard disk drives include some device measuring the internal temperature, and in some situations, the operating parameters of the hard disk drive are altered based upon the measured internal temperature. In many hard disk drives, at least part of the exterior face of the disk base is configured as a primitive thermal transfer element. However, no hard disk drives are known to be able to adjust their internal temperature. What is needed is a hard disk drive able adjust its internal temperature toward its optimal operating temperature range.